Vein mapping is a duplex exam combining B-mode imaging for anatomy and Doppler for flow assessment. It documents vein diameter, depth from skin, distance from the saphenofemoral or saphenopopliteal junction, and confirmation of reflux.
Patient Positioning
Perform the exam with the patient standing whenever possible. Standing maximizes venous distension and gives the most accurate diameter measurements. Use a step stool and have the patient bear weight on the contralateral leg.
Probe Selection
- MX7: L12-3s or L14-6Ns. 10-14 MHz superficial, 7-10 MHz deep thigh.
- M8 Elite: L12-3s or L14-6Ns. Enable iClear for tissue differentiation.
- Resona i9T: L14-3WU or L9-3U. ZST+ provides excellent near-field resolution.
- Consona N9: L13-3N or L9-3 linear probe.
Systematic Mapping Protocol
Start at the saphenofemoral junction (SFJ) in transverse orientation. Identify the CFV and confirm the GSV takeoff. Switch to longitudinal and assess for reflux via Valsalva — greater than 0.5 seconds is pathologic.
Move distally along the GSV in transverse orientation. At each station (every 10-15cm), document: vein diameter outer wall to outer wall, depth from skin, and relationship to the saphenous fascia. Mark the skin with an indelible marker.
- Color Doppler PRF: 1000-2000 Hz
- Wall Filter: Low (50-100 Hz)
- Spectral Gate: 2-3mm at 60 degrees or less
- Reflux threshold: >0.5s superficial, >1.0s deep
- MX7/M8 Elite: Enable Smart Track
- Resona i9T: Use V Flow for angle-independent junction assessment
Documentation
Record at each station: distance from SFJ/SPJ, transverse diameter, skin depth, and anatomical notes. The map becomes the interventionalist treatment planning document.